Controlling the wetting properties of surfaces has been the subject of scientific investigation. Most existing hydrophobic surfaces rely on low surface energy polymers, such as fluoroalkylsilane, or patterned roughness at low length scales. Both strategies have significant drawbacks. For example, fluorinated polymers lack resistance to abrasion and are easily degraded by ultraviolet light. Similarly, high roughness coatings are often fragile and poorly suited for harsh environments. In addition, these coatings often rely on complex manufacturing techniques that are not easily scalable.
Aircraft, automotive, and other transparency applications provide additional challenges. For these applications, a hydrophobic coating should maintain high hardness and resistance to attack by acids and bases. Moreover, these applications can involve metallic substrates, with thermal expansion coefficients and elastic moduli that are incompatible with many existing hydrophobic coatings.
It should be appreciated that there is a need for a scalable method of applying an improved hydrophobic coating having environmentally robust hydrophobicity. The coating should be robust to environmental degradation, mechanical abrasion, and repeated stress, while exhibiting inherently low surface energy without additional surface patterning. For applications involving metallic substrates, the coating should maintain hardness and resistance to attack by acids and bases, while also maintaining a permanent bond to the metallic surface as the surface thermally expands and contracts. The present invention fulfills these needs and provides further related advantages.